1. Field of Industrial Application
The present invention relates to a liquid crystal display device comprising a back light including a liquid crystal display panel having a liquid crystal sealed between two superposed insulating substrates, a light guide plate arranged below the liquid crystal display panel, and a fluorescent tube arranged in the vicinity of the side of the light guide plate, and, more particularly, to a data processing device having said liquid crystal display device assembled as a display unit.
2. Prior Art
In a liquid crystal display device of active matrix type, nonlinear devices (e.g., switching devices) are disposed in a manner to correspond to a plurality of pixel electrodes arranged in matrix, respectively. The liquid crystal in each pixel is always drive, in principle, (at a duty ratio of 1.0). In comparison with the so-called "simple matrix type" which employs a time division driving system, therefore, the active system has better contrast and has become an indispensable technique particularly in a color liquid crystal display device. A typical example of the switching devices is a thin film transistor (TFT).
The liquid crystal display device is constructed to comprise: a liquid crystal display panel (or liquid crystal display element) prepared by superposing two transparent glass substrates at a predetermined gap such that their surfaces each having display pixel electrodes of a transparent conductive film and an orientation film laminated thereon are opposed to each other, by adhering the two substrates to each other by a seal member applied in a frame shape to the edge portion between the two substrates, by filling and sealing a liquid crystal from a liquid crystal sealing entrance formed in a portion of the seal member into the seal member between the two substrates, and by mounting or adhering a polarizing plate to the outer sides of the two substrates; a circuit substrate arranged outside of the outer peripheral portion of the liquid crystal display panel; an intermediate frame molded for holding the aforementioned individual members; a metallic shield casing formed with a liquid crystal display window for accommodating those individual members; and a back light arranged below the liquid crystal display panel for supplying a light to the liquid crystal display panel.
Here, the liquid crystal display device of active matrix type using the thin film transistors is known in Japanese Patent Laid-Open No. 309921/1988 or on pp. 193 to 210 of Nikkei Electronics entitled "Active Matrix Type Color Liquid Crystal Display of 12.5 Type Adopting Redundant Construction" and issued on Dec. 15, 1986 NIKKEI McGRAW-HILL for example.